4504 Background: Single-agent gemcitabine (G) remains standard treatment for advanced pancreatic adenocarcinoma (APC). The GIP-1 randomized phase III trial (clinicaltrials.gov ID NCT00813696 ) was performed to compare the combination of cisplatin (P) and G vs. G alone as 1st-line treatment. Methods: Patients (pts) with locally advanced and/or metastatic pancreatic adenocarcinoma, age 18–75, Karnofsky Performance Status (KPS) ≥50, were randomized to receive G (arm A) or G+P (arm B). In arm A, G was administered at 1000 mg/m2 weekly for 7 consecutive wks, and, after a 2-week rest, on day 1, 8, 15 every 4 wks. In Arm B, P 25 mg/m2 weekly (with the exception of day 22) was added to G, same dose used in Arm A (Colucci et al, Cancer 2002; 94:902–10). No maximum number of cycles was planned. Primary endpoint was overall survival (OS). Clinical benefit (CB), objective response rate (ORR), progression-free survival (PFS), toxicity and quality of life were secondary endpoints. To have 80% power of detecting a 0.74 Hazard Ratio (HR) of death (corresponding to increase in median OS from 4.8 to 6.5 months, with bilateral alpha=0.05, 400 pts were planned and 355 deaths were required for final analysis. Results: From April 2002 to April 2007, 400 pts were enrolled (A:199, B; 201) in 46 Italian Institutions. Median age was 63 yrs (range 35–75), 59% were males, 84% stage IV, 83% KPS≥80. After a median follow-up of 38.2 months and 357 deaths, median OS was 8.3 vs 7.2 months in arm A and B, respectively (HR 1.10, 95% CI 0.89–1.35, p=0.38). Median PFS was 3.9 vs 3.8 months in arm A and B, respectively (HR 0.97, 95% CI 0.80–1.19, p=0.80). ORR was 10.1% in arm A and 12.9% in B (p=0.37). CB response was experienced by 23.0% and 15.1% (Arm A vs B, p=0.057). Patients assigned to combination arm experienced more anaemia (all grades: 50% vs 39%, G3: 5% vs 1%), more neutropenia (all grades: 44% vs 36%, G3&4: 25% vs 14%) and more thrombocytopenia (all grades: 57% vs 29%, G3&4: 16% vs 5%). No relevant differences were seen in non-haematological toxicity. Conclusions: Weekly combination of P and G, compared to single-agent G as 1st-line treatment of APC, failed to demonstrate any improvement in OS, PFS, ORR and clinical benefit. No significant financial relationships to disclose.